How do I access channels for just one layer?

Yes!

The trick is to turn off all the layers you don't want to see, then you will only see the image you want to work with in the Channels.

Here is my original:

Notice the whole image is visible in the Channels panel?

Here is only one layer selected, and the corresponding image in the Channels panel.

Hope that helps!

Let us know if you have any other questions!

Michelle

You do not need working on channels to get the job done.

Add your image. Convert the image layer to smart object and apply a setting only to this image layer

To apply a setting to one layer click between both settings and layer with Alt key pressed. You will see the down arrow and the setting will not affect underneath other layers.

Channels are document-centric, reflecting the visible layer content.

You can add an adjustment layer and clip it to the layer transparency to isolate the changes to that specific layer.

https://helpx.adobe.com/photoshop-elements/using/clipping-masks.html